Ebola virus is a category A priority pathogen and a causative agent of viral hemorrhagic fever. Enhanced pathogenicity displayed by the Ebola virus is achieved through simultaneous inhibition of host immune responses and enhanced production of viral proteins and RNA. However, the exact nature of the interactions between the Ebola virus and host cells that promote viral infection and propagation are poorly understood. Consequently, no vaccines or antiviral agents against Ebola are currently available. These factors combined, underscore the need for detailed structural and functional characterization of the Ebola viral components. Ebola VP35 protein is an important virulence factor required in several viral lifecycle stages, including viral assembly, genome replication, packaging, viral transcription, and antiviral activity toward the host innate immune system. Overall goal of the research program is to explore host-viral interactions that lead to immune evasion. The proposed study, using recombinantly expressed non-infectious VP35 protein, will examine the structure of VP35 and characterize its antiviral activity using biochemical methods. These studies will significantly improve our understanding of how VP35 functions to enhance viral pathogenesis and facilitate the design of novel diagnostic and therapeutic strategies to disrupt critical host-pathogen interactions.